King County, WA Landscaping Rules: Composting (2026)
Key Facts
- Governing section
- King County Code § 10.04.080(B)(1)
- Permit required
- None for a residential compost pile or bin
- Only condition
- Must not attract or breed insects/rodents
- Enforcing agency
- King County health officer via prosecutor's office
- Applies to
- Unincorporated King County only
Summary
Unincorporated King County's litter and dumping law carves out backyard composting: King County Code § 10.04.080(B)(1) says a compost pile or bin is never an unlawful accumulation of solid waste as long as it's kept in a way that doesn't attract or breed insects and rodents. No permit, size cap or setback applies under Title 10.
It is unlawful for the owners or occupants of private property to deposit or accumulate, or to permit the deposit or accumulation of solid waste upon the private property. However, this shall not prohibit the storage of solid waste or recyclable materials in public or private receptacles, in solid waste containers or other approved receptacle or in securely tied bundles when the receptacles or bundles are for immediate or approved periodic disposal. Additionally: 1. The use of a compost pile or bin shall not be prohibited if the use and maintenance thereof is in such a manner as to prevent the attraction, breeding, harboring, or any combination thereof, of insects and rodents; and
Full Breakdown
C. 080(B) builds two carve-outs into that same subsection: composting and permitted recycling. 080(B)(1), the use of a compost pile or bin shall not be prohibited if the use and maintenance thereof is in such a manner as to prevent the attraction, breeding, harboring, or any combination thereof, of insects and rodents. The code sets no maximum pile size, no property-line setback and no permit requirement for residential composting; the only condition is pest management. C. 020: composting means the biological degradation and transformation of organic solid waste under controlled conditions designed to promote aerobic decomposition, and material only counts as composted material once it has gone through that controlled process; natural decay left uncontrolled does not qualify.
C. 100. This rule sits inside the unincorporated-area solid waste code; Seattle, Bellevue and King County's other cities run separate codes and are not covered by it.
Violations & Fines
A compost pile that draws rats, raccoons or insect swarms loses its 10.04.080(B)(1) exception and becomes an unlawful accumulation of solid waste under 10.04.080(A). The health officer can enforce that violation through the prosecutor's office under K.C.C. 10.08.100, subject to King County Code Title 23's citation, notice-and-order and civil-penalty process; repeat or willful violations can also be pursued as a misdemeanor under the county's general code-compliance provisions.
Frequently Asked Questions
Do I need a permit to compost in my King County backyard?
What makes a compost pile illegal in unincorporated King County?
Does King County limit how big a home compost bin can be?
Sources & Official References
Other rules in King County
Compare King County to another location·View the Washington landscaping rules overview
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